Impact of direct drilling and conventional tillage on seasonal changes of soil water content in Chromic Haploxerert (south-west Spain)     

Iván García Tejero  Víctor Hugo Durán Zuazo  Juan Antonio Jiménez Bocanegra  Francisco Perea Torres  José Luis Muriel Fernández 《Archives of Agronomy and Soil Science》2013,59(3):393-409

A continuous monitoring of spatial and temporal variability of soil water content was studied under two soil management systems: direct drilling (DD) and conventional tillage (CT), during four consecutive seasons. The soil water content was read at different soil depths using multisensor capacitance probes in each soil-management treatment. During the first season (2003–2004), soil water content dynamics for both treatments were similar during the rainy season, although the DD plot was able to retain more water in the soil profile, and during the maximum evapotranspirative period faster soil water depletion took place in the CT plot. The 2004–2005 season registered a high evapotranspiration rate (1741 mm) with low rainfall (228 mm), promoting a low soil water recharge for both treatments. The 2005–2006 season registered an increase in rainfall, promoting a greater recovery of the soil water reserve in DD than CC plot. Finally, during the 2006–2007 season with an evapotranspiration rate ET₀ and rainfall of 1504 and 560 mm, respectively, DD retained more soil water content, mainly in the deeper zones, with progressive soil water depletion during the maximum evapotranspirative period in comparison to CT. Thus, DD was demonstrated to be a promising soil management technique for improving the soil water content.  相似文献   

Genetic identity of three mint accessions stored by different conservation procedures: field collection, in vitro and cryopreservation     

Carmen Martín  Angelika Senula  Iván González  Andrés Acosta  E. R. Joachim Keller  M. Elena González-Benito 《Genetic Resources and Crop Evolution》2013,60(1):243-249

At the genebank of IPK (Leibniz Institute of Plant Genetics and Crop Plant Research) in Gatersleben, Germany, three long-term conservation methods (field genebank, in vitro slow-growth and cryopreservation) are used for mint germplasm. The plant material of the field genebank was the source to establish the slow-growth in vitro culture collection, from which the cryopreserved collection was set up, using a droplet-vitrification protocol. The genetic identity of 161 samples of three mint accessions (MEN 198, MEN 166 and MEN 186), stored for several years using those three methods, was studied using RAPD markers. Accession ‘MEN 198’ was the only one with a unique RAPD fragment pattern for all its samples, independently of the conservation procedure employed. The field collections of accessions ‘MEN 166’ and ‘MEN 186’ were made up of different genotypes. None of the genotypes detected in the plots of these accessions was represented in the in vitro and cryopreserved samples analyzed, which showed a unique genotype for each accession. From this work we conclude that, for an appropriate management of a germplasm collection of vegetatively propagated species, the determination of the genetic composition of the donor material and a periodical assessment of the preserved material should be carried out.  相似文献   

Check dams and sediment control: final results of a case study in the upper Corneja River (Central Spain)     

Díaz-Gutiérrez  Virginia  Mongil-Manso  Jorge  Navarro-Hevia  Joaquín  Ramos-Díez  Iván 《Journal of Soils and Sediments》2019,19(1):451-466

Journal of Soils and Sediments - The sediment yield and erosion rate in an area can be estimated by calculating the volume of sediment retained by check dams. However, results can show unrealistic...  相似文献   

Identifying resistance gene analogs associated with resistances to different pathogens in common bean     

López CE  Acosta IF  Jara C  Pedraza F  Gaitán-Solís E  Gallego G  Beebe S  Tohme J 《Phytopathology》2003,93(1):88-95

ABSTRACT A polymerase chain reaction approach using degenerate primers that targeted the conserved domains of cloned plant disease resistance genes (R genes) was used to isolate a set of 15 resistance gene analogs (RGAs) from common bean (Phaseolus vulgaris). Eight different classes of RGAs were obtained from nucleotide binding site (NBS)-based primers and seven from not previously described Toll/Interleukin-1 receptor-like (TIR)-based primers. Putative amino acid sequences of RGAs were significantly similar to R genes and contained additional conserved motifs. The NBS-type RGAs were classified in two subgroups according to the expected final residue in the kinase-2 motif. Eleven RGAs were mapped at 19 loci on eight linkage groups of the common bean genetic map constructed at Centro Internacional de Agricultura Tropical. Genetic linkage was shown for eight RGAs with partial resistance to anthracnose, angular leaf spot (ALS) and Bean golden yellow mosaic virus (BGYMV). RGA1 and RGA2 were associated with resistance loci to anthracnose and BGYMV and were part of two clusters of R genes previously described. A new major cluster was detected by RGA7 and explained up to 63.9% of resistance to ALS and has a putative contribution to anthracnose resistance. These results show the usefulness of RGAs as candidate genes to detect and eventually isolate numerous R genes in common bean.  相似文献   

Versuche zur Immunisierung der Kälber mit dem Schafstamm Myxovirus Parainfluenzae-3     

H. Haralambiev  Iv. Simov  K. Mermerski 《Zoonoses and public health》1970,17(9):970-976

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Pathological and immunological study of an in ovo complex vaccine against infectious bursal disease     

Kelemen M  Forgách K  Iván J  Palya V  Süveges T  Tóth B  Mészáros J 《Acta veterinaria Hungarica》2000,48(4):443-454

The appearance of very virulent strains of infectious bursal disease (IBD) virus at the end of the 1980s made it necessary to develop more effective immunization procedures. To facilitate this, the immunogenicity and the immunosuppressive effect of a mild (G-87), an intermediate (LIBD) and an intermediate-plus (IBDV 2512) IBDV strain were tested after the in ovo inoculation of 18-day-old SPF and broiler chicken embryos. It was established that no noteworthy difference existed between the immunized and the control embryos in hatching rate and hatching weight. The higher the virulence of the vaccine virus strain, the more severe damage it caused to the lymphocytes of the bursa of Fabricius. In SPF chickens, the haemagglutination inhibition (HI) titres induced by a Newcastle disease (ND) vaccine administered at day old decreased in inverse ratio to the virulence of the IBD vaccine strain, while in broiler chickens this was not observed. Despite the decrease of the HI titre, the level of protection did not decline, or did so only after the use of the 'hot' strain. SPF chickens immunized in ovo with a complex vaccine prepared from strain IBDV 2512 and IBD antibody showed the same protection against Newcastle disease as the broilers. In broiler chicken embryos immunized in ovo, only strain IBDV 2512 induced antibody production, and such chickens were protected against IBD at 3 weeks of age. The complex vaccine administered in ovo has been used successfully at farm hatcheries as well.  相似文献   

Streptococcus phocae, an emerging pathogen for salmonid culture     

Romalde JL  Ravelo C  Valdés I  Magariños B  de la Fuente E  Martín CS  Avendaño-Herrera R  Toranzo AE 《Veterinary microbiology》2008,130(1-2):198-207

This work describes the characterization of the causal agent of disease outbreaks that, from 1999, occurred repeatedly during the summer months (temperatures higher than 15 degrees C) in Atlantic salmon (Salmo salar) cage-farmed in Chile affecting both smolts and adult fish cultured in estuary and marine waters, reaching in some occasions a cumulative mortality up to 25% of the affected population. Diseased fish showed exophthalmia with accumulation of purulent and haemorrhagic fluid around eyes, and ventral petechial haemorrhages. At necropsy, haemorrhage in the abdominal fat, pericarditis, and enlarged liver, spleen and kidney are common pathological changes. Gram-stained smears revealed the presence of Gram-positive cocci, beta-hemolytic, negative for oxidase and catalase tests. Although biochemical characterization of the isolates using the miniaturized system rapid ID 32 Strep suggested their assignation to genus Gemella, sequencing and RFLP analysis of the 16S rRNA revealed that bacteria associated with the mortalities belong to Streptococcus phocae. Serological studies demonstrated that all the salmon isolates are antigenically homogeneous, which can facilitate the development of preventive measures and, although sharing some antigenical determinants, they belong to a different Lancefield group than the type strain isolated from seals. On the basis of these facts, we conclude that the species S. phocae is an emerging pathogen for salmonid culture in Chile, and it should be included as a new member of the warm water streptococcosis.  相似文献   

Assessing changes in species distribution from sequential large-scale forest inventories     

Laura Hernández  Isabel Cañellas  Iciar Alberdi  Iván Torres  Fernando Montes 《Annals of Forest Science》2014,71(2):161-171

? Context

It is assumed that global change is already affecting the composition, structure and distribution of forest ecosystems; however, detailed evidences of altitudinal and latitudinal shifts are still scarce.

? Aims

To develop a method based on National Forest Inventory (NFI) to assess spatio-temporal changes in species distributions.

? Methods

We develop an approach based on universal kriging to compare species distribution models from the different NFI cycles and regardless of the differences in the sampling schemes used. Furthermore, a confidence interval approach is used to assess significant changes in species distribution. The approach is applied to some of the southernmost populations of Pinus sylvestris and Fagus sylvatica in the Western Pyrenees over the last 40 years.

? Results

An increase of the presence of the two species in the region was observed. Scots pine distribution has shifted about 1.5 km northwards over recent decades, whereas the European beech has extended its distribution southwards by about 2 km. Furthermore, the optimum altitude for both species has risen by about 200 m. As a result, the zone in which the two species coexist has been enlarged.

? Conclusions

This approach provides a useful tool to compare NFI data from different sampling schemes, quantifying and testing significant shifts in tree species distribution over recent decades across geographical gradients.  相似文献   

Río de la Plata voyagers: Deciphering the migration ecology of a vulnerable marine catfish (Genidens barbus) in a large subtropical river (lower Uruguay River)     

Nicolás Vidal  Alejandro D'Anatro  Iván González-Bergonzoni  Ivana Silva  Patricia Correa  Joaquín País  Giancarlo Tesitore  Franco Teixeira de Mello 《水产资源保护:海洋与淡水生态系统》2021,31(6):1367-1378

1. Genidens barbus is a vulnerable marine migrant catfish with low fecundity, a complex life cycle (i.e. mouth breeding), and is the target of industrial and artisanal fisheries of several countries. This species regularly migrates from marine to freshwater environments of the south-western Atlantic.
2. The aim of this work was to delve deeper into the migration ecology of G. barbus, characterizing both its timing and potential environmental drivers. Furthermore, aspects of the population structure and reproduction of migrants in the lower Uruguay River were studied and the presence of juveniles in the adjacent estuarine recruitment area was evaluated.
3. Data from 11 years (2008–2018) of records of adult G. barbus captured by artisanal fisheries were used alongside relevant environmental variables that were recorded monthly. Reproductive biology (i.e. sex ratio, gonadosomatic index, fecundity, and oocyte size) was analysed for a period of 3 years (2016–2018). The juvenile abundance in the Río de la Plata estuary was evaluated seasonally.
4. A total of 935 adult individuals of G. barbus were captured, representing a total biomass of 3,123 kg. The migration timing was from early spring to early summer. The abundance of migrants strongly increased with river discharge, suggesting that this variable regulates the upriver migration. Furthermore, pre- and post-spawn females and males displaying mouth breeding were recorded during the study period, confirming G. barbus reproduction in the lower Uruguay River.
5. The results obtained suggest that G. barbus ascend to spawn in the freshwater environments upstream from the mouth of the Uruguay River. Then, adult males incubate and carry the embryos downstream, releasing juveniles in the Río de la Plata estuary.
6. This relevant information will help with the implementation of effective management polices (e.g. fishing restrictions during the reproductive period) for the presently unregulated fishery of this vulnerable species in the lower Uruguay River.

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Have the Flowers,Fruitlets, Ripe Fruit and Leaves of Apples Cultivars Similar Compositions of Phenolic and Antioxidant Capacity?     

Yuri  José A.  Neira  Amalia  Fuentes  Mauricio  Sáez  Bárbara  Razmilic  Iván 《Erwerbs-Obstbau》2022,64(2):201-209

Total and specific phenolic compounds and antioxidant capacity were quantified over two seasons in flowers, leaves, fruitlets, and ripe fruit at harvest of the apple cultivars ‘Brookfield’, ‘Granny Smith’ and ‘Fuji’, as well the crabapple cultivars ‘Hillary’ and ‘Manchurian’. The results showed that leaves had the highest phenol concentrations and antioxidant capacity. Phenolic and antioxidant content was progressively lower from flowers, fruitlets, and ripe harvested fruit. There were high concentrations of phloridzin in flowers and leaves, while concentrations were lower in fruitlets, peel, and entire fruit at harvest. The phenolic compound with the highest concentration in peel was quercetin glycoside, while in the entire fruit it was flavanols. The studied crabapple cultivars did not present differences between them in phenolic compounds and antioxidant capacity.

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